=

The magnetic rotation for a saturated tricyclic terpene, B-pinolene, has also been determined.

325. "Contributions to our Knowledge of Semicarbazones." (Preliminary Note). By ISIDOR MORRIS HEILBRON and FORSYTH JAMES WILSON.

In the course of some recent experiments the authors observed that m-nitrobenzylidenedeoxybenzoin on treatment with semicarbazide acetate formed two distinct semicarbazones, a colourless and a yellow modification. The addition of sodium hydroxide solution to an alcoholic solution of either the colourless or the yellow form produced an intense yellow coloration, which was destroyed by acids

As semicarbazones have not as yet been very fully studied, the authors are extending their observations to semicarbazones derived from both saturated and unsaturated ketones and aldehydes.

Phenyl styryl ketone gives on direct treatment with semicarbazide acetate two distinct semicarbazones: a colourless form, melting at 168°, which is rapidly precipitated from a dilute alcoholic solution, and a more soluble yellow form obtained by dilution of the mother-liquors. On attempting to re-crystallise this yellow modification from chloroform, the authors found that it passes into a third modification which crystallises in colourless silky needles melting at 180°. This semicarbazone in the dry state is unstable, being gradually re-converted on exposure to diffused sunlight into the yellow modification. melting-point for this yellow form can be obtained, as it passes when heated above 160° into the colourless modification melting at 180°. Alcoholic solutions of both colourless semicarbazones give with sodium hydroxide intensely yellow products, which are still under investigation.

No

The absorption spectra of these various semicarbazones are being investigated in the hope of throwing further light on the subject.

It has also been found that semicarbazones of both saturated and unsaturated aldehydes and ketones are affected by ultra-violet light, stereoisomerides being apparently produced in some cases, decomposition products in others. Investigations in this direction are also in

progress.

Acid."

326. "Conductivity and Dissociation of Diacetyltartaric By STELLA DEAKIN and ALBERT CHERBURY DAVID RIVETT. Diacetyltartaric anhydride is hydrated too rapidly for the course of the action to be followed by the conductivity method (compare Rivett and Sidgwick, Trans., 1910, xciii., 732, 1677). Since some connection appears to exist in such a case between rate of hydration and first dissociation constant of the acid, a determination of the latter was desirable, and has been made, giving the value 2.5 x 10-2, a higher figure than is given by the acid corresponding with any anhydride the rate of hydration of which has been measured. The second dissociation constant approximates to O'II X 10-2.

327. "A Synthesis of Thioindigo.'" (Preliminary Note). By WILLIAM GEORGE PRESCOTT and SAMUEL

SMILES.

C6H4

.CO

· C6H4<_>C(CO2Et)2+2H2O. Condensation of these thio-acids wirh ethyl acetoacetate, substituted malonic acids, and similar substances may also be effected; these interactions are now being more closely investigated.

328. "Asymmetry in the supposed Absence of an Asymmetric Atom." By JAMES ERNEST MARSH.

Everest's paper (Proc. Chem. Soc., xxvii., 285) disposes effectively of the claim that a new type of asymmetry exists which is not dependent on the presence of an asymmetric atom in the molecule. At the same time, the views of Everest involve him in a difficulty of another kind; in the conversion of the unsaturated acid into its dibromide, the asymmetric carbon atom (1) is represented as losing its asymmetry, while a new asymmetry carbon atom (7) is created in a different part of the molecule outside the ring: :CH3 CH2 CH2 CO2H CC (4) (7) H

H (1) CH2 CH2

H (1) CH2 CH2 (4) (7) Br

83) that the constitutional formula of the unsaturated acid Perkin, Pope, and Wallach, in stating (Proc. 1909, xxv., "comprises no atom which can be described as asym metric, no matter which definition of an asymmetric atom be adopted," have overlooked the definition given by the He there author (Phil. Mag., 1888, [5], xxvi., 426). defined an asymmetric carbon atom as one which, when replaced by its image, gives a formula different from the This idea involved the consideration of original formula. an atom isolated from the rest of the molecule, and was

justified in view of van't Hoff's theory ("Dix Années,” &c., 1887, pp. 27 and 28) that the tetrahedron the centre of which is occupied by the carbon atom acquires an asymmetric form owing to the effect of four different affinities on it; thus the asymmetrically deformed atom can be considered apart from the particular groups to which it is attached. The groups may be four or less, according as the atom is situated in open-chain or in one or more rings. The atom being asymmetric will have a non-superposable image. The replacement of the atom by its image was represented in the author's paper as brought about by an exchange of position of two of the groups attached to the atom. The same inversion may be done by flyping the tetrahedron (that is, by turning it inside out), a process applicable to the stereocentric benzene formulæ, and one which affords a simple explanation of the phenomenon called the Walden inversion. In this method of treatment there is no need for a kind of dissection of a formula, as employed by Everest to prove four different groups, a process which must become difficult when there are several asymmetric atoms in the molecule. The views expressed in the author's paper lead to the conclusion that the methylcyclohexylideneacetic acid has three asymmetric carbon atoms in the molecule (1), (4), and (7), and that all three remain asymmetric in the bromine additive compound.

Perkin and Pope (Trans., 1911, xcix., 1510) claim that in the methylcyclohexylideneacetic acid "the optical activity is due to the enantiomorphous configuration of the molecule as a whole." This is certainly true, not only of this acid, but of every optically active substance whatever, and the author stated it in the paper already mentioned. The converse has also proved true that unless the molecule as a whole is asymmetric it will be optically inactive, however many asymmetric atoms it may contain. The term "centroasymmetry" is therefore not only unnecessary, but misleading; and van't Hoff's original proposition with regard to carbon still holds good, that every optically active compound has an asymmetric atom in the molecule, although the presence of asymmetric carbon does not necessarily involve optical activity.

329. "Latent Heats of Vaporisation of Mixed Liquids." (Part II.). By DAN TYRER.

In continuation of previous investigations (Trans., 1911, xcix., 1633) it was pointed out that a mixture of two liquids has really two latent heats, namely:-1. Heat absorbed when I grm. of the mixture vaporises at constant temperature and pressure from an infinitely large quantity of the mixture of known composition. It is supposed that no change in the composition occurs in this process. 2. Heat absorbed when I grm. of a mixture is completely vaporised at constant temperature. If x is the composition of the liquid in (1) and y the composition of the vapour which leaves it, and if y is also the composition of the I gim. of liquid in (2), then it can be easily shown that

(Lp)x = (Lc)y+H,

where Lp and La are the two latent heats respectively defined above, and H is the heat developed when I grm. of the mixture of composition y is added to an infinitely large quantity of the liquid of composition x. Values of Lp for several mixtures have been experimentally determined, and also the compositions y of the vapour boiling off from mixtures of known compositions, and from this data values of Lc have been calculated. It was shown that whilst the results for Lp do not appear to bear any simple relation to the compositions of the mixtures, those for Lc follow Trouton's equation

In the case of the allyl- and propyl-amides of tartaric and malic acids previously investigated by one of the authors (Trans., 1906, lxxxix., 1854 and 1861), the differences in rotation were much more pronounced, and in both instances the propyl compound had the higher rotation, thus:In pyridine solution. [M]D 20° (tartaric).

Allylamide n-Propylamide..

+251° +289

[M]D 20 (malic). - 72.7° -90'5

These greater differences in rotation in the case of the tartaric and malic compounds are probably due to there only being three intervening atoms between the unsaturated and the asymmetric carbon atoms, whilst in the above menthyl compounds there are in all cases five intervening atoms between the unsaturated carbon atom of the allyl and the nearest asymmetric carbon of the menthyl group.

331. "The Action of Aliphatic Amines on s-Dibromosuccinic Acid." (Part Í.). By EDWARd Percy Frankland and HENRY EDGAR SMITH.

The authors have prepared the dipropylamino- and RNH CH CÓ H

dibutylaminosuccinic acids,

s-dibromosuccinic acid in alcoholic solution. The reaction action of n-propylamine and n-butylamine respectively on appears to proceed in a manner analogous to that described by E. P. Frankland (Trans., 1911, xcix., 1775) in the case of benzylamine and s-dibromosuccinic acid. The alkylamino-acids yield copper salts, hydrochlorides, and

dinitroso-derivatives.

332. "The Velocity of the Reaction between Iodic and Sulphurous Acids in various Media." BY THOMAS STEWART PATTERSON and WILLIAM COLLINS FORSYTH.

The influence of methyl alcohol, ethyl alcohol, n-propyl alcohol, and of acetone on the velocity of the reaction between iodic acid and sulphurous acid was described.

NOTICES OF BOOKS.

Laboratoriumsbuch fur die Anorganische Grossindustrie. ("Laboratory Book for the Inorganic Major Industries "). By Dr. C. v. HOнORST. Halle-a.-S.: Wilhelm Knapp. 1911. (5.60 Mk.).

THIS laboratory manual is intended more particularly for the guidance of chemists who are entering upon their pronology, during which they have gained a certain amount fessional life after a course of training in chemical techof proficiency in the usual analytical operations, and have in addition made a special study of some particular branch. It not infrequently happens that they find the equipment of the works laboratory very different from that of the laboratory belonging to the technical college, and a considerable amount of time and energy is often wasted in getting used to the altered conditions of work. The book is not to be regarded as a concise survey of all the methods which have been suggested for analysing the substances dealt with, but rather as a guide to those which, having the greatest claims to accuracy, rapidity, and simplicity, are practically universally adopted. It gives succinct directions without any superfluous detail for the carrying out of the analyses of fuels, boiler waters, and the raw material and finished products of the acid, salt, chlorine, and ammonium industries. All the tables used in these processes are included, and a chapter on the analysis of artificial manures by Dr. M. Rosenberg has been added.

leather, 12s. 6d.

Who's Who Year Book by the same publishers, is intended chiefly as a supplement to the larger volume, and is, in fact, made up of the tables formerly in that book itself. In addition will be found some original tables not to be met with elsewhere. such as Race Meetings, London Theatres with their Lessees and Managers, Professors of Universities, &c. Price Is. net.

The Writer's and Artist's Year Book.-This book has been devised to meet the needs of authors and contributors to journals to enable them to decide where to place their stories and articles. The book is written for those who wish to make money by their writing, and in most cases some indication is given of the fees paid by publishers for

contributions.

The Englishwoman's Year Book and Directory.-The work is divided into two parts. The first treats of Education, Professions, and Social Life; and the second Philanthropic effort. It is edited by G. E. Mitton, with the assistance of an Honorary Committee of prominent women of the day, and contains a mass of valuable information relative to women's professions, trades, sports, pastimes, and philanthropies. Special attention has been given to the position of women in Municipal, Industrial, and Social Life. The book can be studied with profit by every woman. Red cloth, 400 pages, price 2s. 6d. net.

and does not melt until a much higher temperature is reached. It is the most stable of all the bismuth-sodium compounds. It is soluble in excess of liquid bismuth, and causes a lowering of the melting-point when it dissolves; the maximum is reached with a melt of composition Na3 Bi+5Bi. The author has applied the same method to many other elements which have a melting-point below the boiling-point of paraffin. These include K, Na, Rb, Cs, Li, Cd, Hg. Ga, In, TI, Sn, Pb, Bi, and the metalloids P, Se, Te. The bismuthides of the alkali metals are readily oxidised in air, being converted into a black powder which consists of the alkali and bismuth suboxide. They are decomposed by water. With hydrogen they yield metallic hydrides.

Zeitschrift für Anorganische Chemie.
Vol. lxxii., No. 4, 1911.

Tantalum and Niobium Pentafluorides. - Otto Ruff and Emil Schiller.-Large quantities of the pentafluorides of tantalum and niobium can be prepared by the action of anhydrous hydrofluoric acid on the pentachlorides, which may be obtained by heating the oxides in a current of chlorine and carbon tetrachloride. Tantalum pentafluoride forms colourless double refracting crystals of melting-point 96.8°. It is, generally speaking, stable towards non-metals, but is attacked by metals. With water it yields the pentoxide. The melting-point of niobium pentafluoride is 75.5°. In its reactions it resembles the tantalum salt, but it does not react so readily. Niobic and tantalic acids can be separated by dissolving in hydrofluoric acid, adding excess of KI, and subjecting the mixture to fractional crystallisation. To separate tantalic and niobic acids from titanic acid Knop's method is the best; i.e., the conversion of the oxides into chlorides and the fractional sublimation of the latter in vacuo.

SOURCES.

Norr.-All degrees of temperature are Centigrade unless otherwise expressed.

Comptes Rendus Hebdomadaires des Séances de l'Académie des Sciences. Vol. cliii., No. 22, November 27, 1911. B-Rays of Radium Family.-J. Danysz.-The author has already shown that from a tube containing radium emanation at least seven bundles of B-rays escape, of different and perfectly definite velocities. He has now measured these velocities, and has proved the existence of twenty-three bundles of rays; these transport very different electric charges.

Condensation of Acid Amines in presence of Glycerin.-L. C. Maillard.-When a mixture of glycocoll with four or five times its weight of glycerin is kept for some hours at 170°, most of the glycocoil is transformed into cycloglycylglycine. As an intermediate product the tetrapeptide triglycylglycine is formed. By a secondary reaction triglycylglycine yields the hexapeptide, pentaglycylglycine. The reaction is general, and can be applied in the synthesis of mixed cycloglycylglycines. Probably a glyceric ether is first formed, and is then destroyed with regeneration of the alcohol; thus the reaction is a generalisation of that of Th. Curtius.

Berichte der Deutschen Chemischen Gesellschaft.
Vol. xliv., No. 16, 1911.

Bismuthides and Compounds of Metals with One Another.-A. C. Vournasos.-When bismuth and a metal are melted separately under paraffin, and one liquid is poured into the other, a crystalline precipitate is obtained. If sodium is used the precipitate is Na3Bi; it is insoluble in excess of sodium at the temperature of boiling paraffin,

MEETINGS FOR THE WEEK.

MONDAY, 8th.-Society of Chemical Industry, 8.

"Production of

Formic and Acetic Acids by the Atmospheric Oxida-
tion of Turpentine," by C. T. Kingzett and R. C.
Woodcock. "Rapid Volumetric Method for the
Determination of Free Sulphur," by C. Davis and
J. L. Foucar. "Relative Adsorption of Dyes by
Sand and Natural Fibres." by W. P. Dreaper and
W. A. Davis. "Ingrain Dyeing Influence of cer-
tain Groups on the Re-solution Factor," by W. P.
Dreaper.

TUESDAY, 9th.-Royal Institution, 3. (Christmas Lectures, adapted
to a Juvenile Auditory). "The Childhood of
Animals," by P. Chalmers Mitchell, LL.D.,
D.Sc., F.R.S.

Society of Dyers and Colourists, 8. "Some Problems in Garment Dyeing," by F. G. Newbury. "Aluminium in the Service of Chemical Industry," by R. Seligman. WEDNESDAY, 1oth.-Royal Society of Arts, 5. (Juvenile Lectures). Soap Bubbles," by Prof. C. V. Boys, F.R.S. THURDAY, 11th.-Royal Society. "Propagation of Waves through a Stratified Medium, with Special Reference to the Question of Reflection," by Lord Rayleigh. "Variation of the Specific Heat of Water, with Experiments by a New Method," by H. L. Callendar. "Mechanism of the Semi-permeable Membrane, and a New Method of Determining Osmotic Pressure," by F. T. Trouton. "Mobility of the Positive and Negative Ions in Gases at High Pressures," by A. L. Kovarik. "A New Method of Determining the Radiation Constant,' by G. A. Shakespear. Mechanics of the Water Molecule," by R. A. Houston.